The incomplete degradation of tumour cells by macrophages (Mϕ) is a contributing factor to tumour progression and metastasis, and the degradation function of Mϕ is mediated through phagosomes and lysosomes. In our preliminary experiments, we found that overactivation of NADPH oxidase 2 (NOX2) reduced the ability of Mϕ to degrade engulfed tumour cells. Above this, we screened out liquiritin from Glycyrrhiza uralensis Fisch, which can significantly inhibit NOX2 activity and inhibit tumours, to elucidate that suppressing NOX2 can enhance the ability of Mϕ to degrade tumour cells. We found that the tumour environment could activate the NOX2 activity in Mϕ phagosomes, causing Mϕ to produce excessive reactive oxygen species (ROS), thus prohibiting the formation of phagolysosomes before degradation. Conversely, inhibiting NOX2 in Mϕ by liquiritin can reduce ROS and promote phagosome-lysosome fusion, therefore improving the enzymatic degradation of tumour cells after phagocytosis, and subsequently promote T cell activity by presenting antigens. We further confirmed that liquiritin down-regulated the expression of the NOX2 specific membrane component protein gp91 phox, blocking its binding to the NOX2 cytoplasmic component proteins p67 phox and p47 phox, thereby inhibiting the activity of NOX2. This study elucidates the specific mechanism by which Mϕ cannot degrade tumour cells after phagocytosis, and indicates that liquiritin can promote the ability of Mϕ to degrade tumour cells by suppressing NOX2.

With improvements in information technology and expansion in education reforms, more innovative teaching reform programs have also been launched. Information technology has increased interest in the use of the flipped classroom innovative teaching model. In order to explore new ideas for the improvement of teaching, this paper focuses on the flipped classroom teaching approach with the integration of information technology. Micro-teaching is an important innovative flipped classroom teaching approach with a number of advantages as it is short, concise, and interesting, which therefore helps improve students' self-learning ability. Designing and preparing micro-teaching would become a prerequisite skill for college teachers. Based on the analysis of the entries in the "National Universities Micro-teaching Competition of Life Science", this paper explores the application of micro-teaching in life sciences teaching from the perspective of curriculum introduction, mode of presentation, teaching design, and other aspects of teaching. This information could serve as a guide to frontline college teachers to help them understand and master the skills of designing micro-teaching, so as to generate interest and improve learning efficiency among college students.
Biological Science Disciplines ; Curriculum ; Humans ; Learning ; Students ; Universities

Objective　To compare the endocytic routes of exogenous antigen between murine dendritic cells (DCs) and macrophages (Mφs). Methods　Murine bone marrow-derived DCs and peritoneal Mφs were pulsed with horseradish peroxidase (HRP)-5 nm colloidal gold for 10 minutes, then grouped and chased for 0-120 minutes in culture medium. Intracellular distribution of 5 nm colloidal gold was explored by means of the cellular enzymatic-chemistry of acid phosphatase and MHC Ⅱ immuno-cytochemistry under electron microscope. Results　After 10 minutes of pulse with HRP-5 nm colloidal gold and 30 minutes of chase, most HRP-5 nm gold particles internalized by DCs entered into MHC class Ⅱ compartments (MⅡCs), and a small portion entered into acid phosphatase-positive lysosomes. In contrast to DCs, most Mφs lysosomes were accessed by HRP-5 nm gold particles, and a small portion of HRP-5 nm gold particles entered into MⅡCs. After 60 minutes of chase, 5 nm gold particles could hardly be seen within Mφs, whereas most 5 nm gold particles were still retained in DCs. Conclusions　The endocytic route of exogenous antigen in DCs seems to be different from that in Mφs. Antigens taken by Mφs mainly enter into lysosomes within 30 minutes. In the case of DCs, most internalized antigens enter into MⅡCs, which may be related to their unique antigen-presenting function . In addition, Mφs seem to have more powerful capacity to scavenge exogenous antigen than DCs.